JP2001141426A - Appearance inspecting device and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically inspect display information printed on objects to be inspected such capacitors which relied on visual inspections by workers. SOLUTION: A binary image is created from a multivalued image covering the printed surface of a capacitor captured by a COD camera (S2) to perform GO/NO-GO inspections on a polarity mark afterward (S5 and S6). Then inspections are performed on the heights, widths, areas, etc., of other character strings (S8-S14). Reference data is subjected to expansion and contraction processing in a character unit (S15). By superimposing the expansion data and narrow-line data obtained by the processing on an actual image (S16), the degree of matching is inspected (S17) to determine whether the printing is conforming or not conforming in a character unit (S18 and S1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external appearance in which an image of an object to be inspected, such as an aluminum electrolytic capacitor, is captured and various kinds of display information such as characters, symbols, and graphics attached to the surface of the object are inspected. It belongs to a technical field including an inspection device.

[0002]

2. Description of the Related Art In an aluminum electrolytic capacitor, a pair of electrode terminals including a negative electrode terminal and a positive electrode terminal extend from a lower surface of a cylindrical main body. These two terminals have different lengths for distinguishing between the positive electrode and the negative electrode. Specifically, the negative electrode terminal is made shorter and the positive electrode terminal is made longer. On the other hand, predetermined display information is printed on the upper surface of the main body by an ink jet or the like. The predetermined display information is, for example, display information of characters, symbols, figures, etc. such as a polarity mark, a company mark of a manufacturer, a lot number, a capacity, and a voltage.

[0003] Here, the polarity mark is a mark provided at a position corresponding to the negative electrode terminal, and the polarity mark enables the distinction between the positive electrode and the negative electrode even from the upper surface of the main body. For example, the polarity mark is generally represented by, for example, a crescent or rectangular black solid figure. Therefore, displaying the polarity mark is important for knowing the polarity.

[0004] Display information such as the company mark, lot number, capacity, voltage, etc., is usually printed separately on a portion of the top surface of the main body where no polarity mark is attached. The display of the company mark is important for specifying the manufacturer, and the display of the lot number is important for specifying the product. In addition, the indication of the capacity is important for confirming that the required capacity range is satisfied, etc., and the indication of the voltage is for confirming that the used voltage value does not exceed a predetermined allowable voltage value. It is important in doing.

Therefore, these printed display information are
It is extremely important that the data can be read reliably and that the data is easy to read. From these viewpoints, it is necessary to inspect the display information at least before shipment.

[0006]

Conventionally, however, the inspection of the display information attached to the aluminum electrolytic capacitor to determine whether it is good or bad has been left to the naked eye of an operator.

Therefore, even in a situation where the manufacturing process of an aluminum electrolytic capacitor has been automated and its production efficiency has been improved, visual inspection of display information cannot keep up with the production speed, and the efficiency before product shipment is reduced. I have no choice. In addition, a worker dedicated to visual inspection is required, which increases the production cost.

In addition, since the visual inspection is performed by an operator, the judgment criteria of good or bad for each worker are different, and even if the same operator, the judgment criterion changes from time to time. In some cases, a product that should be determined to be defective is overlooked. As a result, the display information tends to vary from one aluminum electrolytic capacitor to another.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to automate inspection of display information attached to an inspection object such as an aluminum electrolytic capacitor.
In addition, it is an object of the present invention to enable an accurate inspection with little variation as an inspection of display information.

[0010]

Means for Solving the Problems and Effects of the Invention Characteristic means for achieving the above object will be described below. In addition, a characteristic action and effect of each means will be described as necessary.

Means 1. An appearance inspection apparatus for judging the quality of a plurality of types of display information attached to a surface of an inspection object, an imaging unit receiving reflected light from the surface, and a multi-valued image obtained by the imaging unit An image processing device that converts the image into a binary image and determines the quality of the display information based on the binary image, wherein the image processing device divides the plurality of types of display information, and A visual inspection apparatus, which performs a pass / fail judgment process.

According to the means 1, the reflected light from the surface of the inspection object is received by the imaging means, and the multi-valued image obtained by the imaging means is converted into a binary image by the image processing device. The image processing device determines the quality of the display information using the binary image. Here, since the image processing apparatus does not perform a determination process for all display information at once, but performs a pass / fail determination process for each display information, the pass / fail determination can be performed for each display information, and an accurate pass / fail can be determined. The judgment can be made automatically.

Although it is possible to receive reflected light based on natural light by the imaging means, it is possible to positively illuminate the surface of the inspection object by the illumination means and receive the reflected light by the imaging means. This is preferable for capturing a stable image.

Means 2. 2. The visual inspection device according to claim 1, wherein the image processing device further performs pass / fail determination processing in a minimum unit such as a single character unit for each display information. According to the means 2, when the display information is composed of a plurality of characters, the pass / fail judgment is performed for each character, that is, the minimum unit, and the accuracy of the pass / fail judgment can be further improved.

Means 3. The method according to claim 1 or 2, wherein when the multi-level image is converted into a binary image by the image processing apparatus, a binarization threshold is set every time based on the luminance of the multi-level image. Appearance inspection device.

As a general method, the binarization threshold can be set to a predetermined constant value in consideration of various conditions.
However, when the brightness of the illumination changes, or when display information such as printing has shading, an accurate inspection cannot be performed if the binarization threshold is a constant value. On the other hand, according to the means 3, since the binarization threshold is set every time based on the luminance of the multi-valued image, accurate pass / fail determination is performed without being affected by a change in illumination or a density of display information. be able to.

In addition, there are various methods, for example, a threshold value is set at an intermediate position between the darkest value and the brightest value in the multi-valued image, and a deviation of the luminance of the multi-valued image is considered. The method of setting an intermediate position between the brightest value and the darkest value is superior in that the arithmetic processing can be executed quickly and simply. In this case, it is optimal to set the center position between the brightest value and the darkest value as the binarization threshold. Of course, it is preferable that the setting of how to determine the binarization threshold can be appropriately set by the input means.

Means 4. The image processing apparatus measures a surface position of the inspection object based on the binary image, sets a plurality of windows for the binary image based on the measurement result, and displays each display information using each window. Appearance inspection apparatus according to any one of means 1 to 3, wherein the quality inspection is performed. According to the means 4, instead of directly determining the binary image, a plurality of windows are set based on the surface position of the inspection object, and the quality is determined using each of the windows. There are advantages such as the ability to make a focused determination of the displayed information.

Means 5 The image processing apparatus sets a first window of the windows so as to straddle an area to which display information is attached and an area to which no display information is attached,
By inspecting the binary image in the first window,
The visual inspection apparatus according to claim 4, wherein one end of the display information is determined.

According to the means 5, the first window is set so as to straddle the area with the display information and the area without the display information. This makes it possible to determine one end of the display information by scanning the binary image in the first window from one side to the other. Such a determination result can be used as a material for determining whether display information is good or bad. Incidentally, such means 5 is effective in determining the quality of the polarity mark in the aluminum electrolytic capacitor.

Means 6 The image processing apparatus sets a second window of the windows to have a size and a position that include a plurality of pieces of predetermined display information and partially deviate from the surface of the inspection object, The visual inspection apparatus according to the means 4 or 5, wherein when inspecting each display information in the second window, a region on an outer peripheral side of the surface is masked.

According to the means 6, the second window is set so as to include a plurality of predetermined pieces of display information and have a size and a position which partially deviate from the surface of the inspection object. Thereby, the display information included in the binary image in the second window is inspected collectively, or the height or width of each display information is inspected by scanning the binary image from one side to the other. can do. Such test results,
It can be used as a material for determining the quality of display information. This means 6 is effective for judging the quality of the aluminum electrolytic capacitor in terms of company mark, lot number, capacitance value, voltage value and the like. Here, when the second window is set so as to include a plurality of pieces of display information as described above, particularly when the surface is circular or the like, a region on the outer peripheral side of the circular region is also included in the window. However, by masking the outer peripheral area, the outer peripheral area of the surface is not erroneously recognized as display information, so that the second window is set without being restricted by the size of the surface. can do.

Means 7 The image processing apparatus sets a third window of the windows so as to straddle the inside and outside of the surface of the inspection object, and performs the mask process using at least the luminance of the third window. An appearance inspection apparatus according to claim 6, wherein:

In the means 7, the third window is set so as to extend over the inside and outside of the surface to be inspected. In addition, using the luminance in the third window,
Is performed. Thus, since the mask processing is executed while utilizing the luminance of the actual image, the mask processing can be performed reliably, and the outside of the surface area can be reliably separated from the display information and inspected. Note that the mask processing may be further ensured by using the luminance in the first window as well as the third window and averaging the luminances, for example.

Means 8 The image processing apparatus includes a storage unit that stores storage data of a minimum unit such as a single character unit for each piece of display information, and stores the storage data stored in the storage unit into a minimum value of an actual binary image corresponding to the storage data. Reference data is generated by performing processing to match the vertical and horizontal sizes of the unit data, and the pass / fail of each minimum unit is determined by comparing the reference data with the minimum unit data of an actual binary image. An appearance inspection apparatus according to any one of means 1 to 7, characterized in that:

According to the means 8, the storage means stores the storage data of the minimum unit. The storage data is subjected to a process of adjusting the size of the storage data to the vertical and horizontal sizes of the minimum unit data of the actual binary image, and the reference is performed. Generated data. Then, based on the reference data, a comparison with an actual binary image is made. As a result, the storage means only needs to hold data of about several dots vertically and horizontally as storage data, and the storage capacity can be reduced. In addition, the reference data is processed so that its length and width match the length and width of the minimum unit data of the actual binary image, so that it is possible to flexibly cope with characters or the like that are elongated in the vertical or horizontal direction.

Means 9 The image processing apparatus includes a storage unit that stores storage data of a minimum unit such as a single character unit for each display information, and performs expansion and contraction processing using the data of the minimum unit of the storage data. Generates data and contraction data, compares the minimum unit data of the actual binary image with the dilation data and contraction data, respectively, and checks the degree of coincidence, and judges the pass / fail of each minimum unit based on the degree of coincidence. The visual inspection device according to any one of means 1 to 8, characterized in that:

According to the means 9, instead of simply comparing the reference data with the minimum unit data of the actual binary image, the actual data is obtained based on the expansion data and the contraction data obtained by expanding the reference data. Since the comparison is made with the minimum unit data of the binary image, it is possible to reliably determine a defect or blur of a character or the like as a defect. It is preferable that the comparison process is performed by superimposing the dilation data and the actual minimum unit data and checking the degree of coincidence, or by superimposing the contraction data and the actual minimum data and observing the degree of coincidence. In addition, it is not always necessary to set the coincidence to 100%, but it is preferable that the input can be set according to an allowable degree such as 95%.

Means 10. The appearance inspection apparatus according to claim 9, wherein the contraction processing is a thinning processing, and the contraction data is thin line data. In contraction processing generally referred to, contraction data does not always have a series of connections. In this case, if a discontinuous portion of contraction data and a discontinuous portion of actual data happen to coincide with each other, it should be originally determined to be defective. The product may be judged to be good. However, according to such means 10,
By adopting the thinning process among the shrinking processes, the thin line data becomes continuous data, and optimal data can be provided as the reference data.

Means 11 11. The appearance inspection apparatus according to claim 1, wherein a surface of the inspection object is a printing surface, and display information is printed on the printing surface. According to the means 11, it is possible to judge the print information as light if the print density is low, the print is blurred, or the print is defective by targeting the print information. Becomes Means 8,
If print data is used as the storage data described in 9, the required storage capacity can be further reduced.

Means 12 The visual inspection apparatus according to any one of means 1 to 11, wherein a surface of the inspection object is circular. According to the means 12, it is possible to determine the quality of the display information attached to the inside of the circular surface. In this case, when a rectangular window including a plurality of predetermined pieces of display information is set, as in the second window, the second window is likely to be located outside the circular area on the surface. By the mask processing, the area outside the circular area can be reliably distinguished from the display information.

Means 13 The inspection object is an aluminum electrolytic capacitor whose surface is formed of aluminum,
13. The visual inspection apparatus according to the means 11 or 12, wherein the printing has a different luminance from the ground color of the printing surface. According to the means 13, it is possible to automatically determine the quality of the display information printed on the surface of the aluminum electrolytic capacitor, which could only be determined by a visual inspection by a conventional operator.

Means 14. Means 13 characterized by including at least a polarity mark and display information arranged in a plurality of levels as the plurality of types of display information, and determining whether or not the polarity mark is a pass / fail test item different from other display information. Visual inspection equipment. According to the means 14, the inspection of the polarity mark peculiar to the aluminum electrolytic capacitor is performed separately from information such as other characters, so that the quality of the polarity mark can be reliably determined. The quality of the polar mark can be determined by, for example, a width test of the polar mark and an area test in a window set in the polar mark.

Means 15. A printing apparatus comprising the appearance inspection device according to any one of means 1 to 14. According to the means 15, when the display information is attached by printing, the appearance inspection of the display information can be performed simultaneously with the printing process, and the production efficiency of the inspection object is improved.

Means 16. Printing means for printing as display information on the surface of the object to be inspected, and transfer means for transferring the object to be inspected from the printing means to a visual inspection apparatus, wherein the transport means is used for the visual inspection apparatus from the time of printing by the printing means. 16. The printing apparatus according to claim 15, wherein the inspection object is transported while the posture of the inspection object is kept constant until an inspection is performed.

According to the means 16, since the posture of the inspection object is kept constant by the transfer means between the printing step and the inspection step, the inspection object, which is the inspection point, is inspected in the printing step and the inspection step. Since the surface is arranged in a fixed posture, it is not necessary to correct the posture of the surface one by one during the inspection process. When the object to be inspected is an aluminum electrolytic capacitor as described in the means 13, it is possible to hold the capacitor in a fixed posture by transferring while holding the pair of electrode terminals of the capacitor by the transfer means. Is possible.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment will be described below with reference to FIGS.

In this embodiment, a case where the object to be inspected is an aluminum electrolytic capacitor 1 (hereinafter, referred to as a capacitor) will be described.

As shown in FIGS. 1 (b) to 1 (d) and the like, a capacitor 1 has an aluminum main body 2 having a substantially cylindrical outer shape and a pair of different lengths extending from the lower surface of the main body 2. It is composed of electrode terminals 3 and 4. The difference between the lengths of the two electrode terminals 3 and 4 is provided so that the positive electrode and the negative electrode can be distinguished at a glance. Specifically, the negative terminal 3 is short and the positive terminal 4 is long.

The upper surface (front surface) of the main body 2 of the capacitor 1 is a circular and flat printing surface 5. As shown in FIG. 5, predetermined display information is printed on the printing surface 5 by ink jet. Here, the predetermined display information is,
The polarity mark 6, the company mark 7 of the manufacturer, the lot number 8, the capacitance value 9, and the voltage value 10 may be displayed information such as other characters, symbols, and figures.

Here, the polarity mark 6 is a mark provided at a position corresponding to the negative electrode terminal 3, and the polarity mark 6 makes it possible to distinguish between the positive electrode and the negative electrode even from the upper surface of the main body 2. . Here, the polarity mark 6 is
It is represented by a crescent-shaped black painted figure.

The company mark 7 is represented by a black solid figure having a substantially elliptical shape as an example, and the display information allows the manufacturer of the capacitor 1 to be identified. The lot number 8 is used to specify a product type and the like, and is often expressed by a predetermined number, alphabetical character, or the like. Here, a case where the lot number 8 is composed of three characters “ABC” will be described as an example. I do.

The capacitance value 9 is a numerical value representing the maximum capacitance of the capacitor 1, and is indicated here as "1". The voltage value 10 is a numerical value representing the allowable voltage of the capacitor 1, and is indicated here as "50 V".

Next, an outline of the printing apparatus 11 for printing on the printing surface 5 of the capacitor 1 will be described. FIG.
As shown in FIG. 1A, the printing apparatus 11 includes a charging and aligning apparatus 12, a direction correcting apparatus 13, a print processing apparatus 14 as a printing unit, and a curing processing, from the upstream side to the downstream side when viewed in the transport direction of the condenser 1. An apparatus 15, a visual inspection apparatus 16 and a sorting apparatus 17 are provided in order.

The capacitor 1 before printing is loaded into the loading and aligning device 12. As shown in FIG. 1 (b), the capacitors 1 before being put into the input aligning device 12 have a random arrangement, but after being aligned in the input aligning device 12 to the next direction correcting device 13. Will be sent out. The alignment here means that the printed surface 5 of the capacitor 1 is arranged upward and both terminals 3 and 4 are arranged downward as shown in FIG. Are in a state of being separated.

In the direction correcting device 13, a difference in length between the two electrode terminals 3 and 4 is inspected while the main body 2 is gripped by a chuck (not shown). A process of rotating the chuck by 180 degrees is performed so that all the capacitors 1 match. As a result, as shown in FIG. 1D, the front and rear relations of the electrode terminals 3 and 4 also match, and the next print processing device 14
Sent to

At the time of sending to the print processing device 14,
Since the main body 2 is being held by the chuck in the direction correcting device 13, the capacitor 1 is held on the print processing device 14 side by holding both electrodes 3 and 4 by the chuck 18 (see FIG. 2) as a transfer means. Is given and received. In the print processing device 14, the printing surface 5 which is the upper surface of the capacitor 1
The display information of the polarity mark 6, company mark 7, lot number 8, capacitance value 9, and voltage value 10 is printed on the display. In the present embodiment, an ink jet system is adopted as a transfer system.

Thereafter, in the curing device 15, a curing process is performed on the printing surface 5 using ultraviolet rays. This makes it difficult for the display information printed on the printing surface 5 to drop.

Next, the capacitor 1 is sent to the visual inspection device 16. As shown in FIG. 2, in the appearance inspection device 16, illumination 19 as illumination means for illuminating the printing surface 5 side,
A CCD camera 20 as imaging means for receiving reflected light from the printing surface 5 based on the illumination 19 is arranged in proximity to a transport portion of the condenser 1. Appearance inspection device 16
Then, the quality of the printing surface 5 is inspected based on the image data captured by the CCD camera 20. In addition,
From the print processing device 14 to the visual inspection device 16 by the chuck 18, the capacitor 1 is held in a constant posture with the printing surface 5 facing upward, so that the work flow from the printing process to the inspection process is smooth. It can be.

According to the inspection result by the appearance inspection device 16, the capacitor 1 is classified into a non-defective product and a defective product, and the capacitors 1 are subjected to the classification process by the classification processing device 17. That is, the capacitor 1 determined to be defective is discarded. On the other hand, the capacitor 1 determined to be non-defective is transported to the chip mounting device 21 provided separately from the printing device 11.

In the chip mounting device 21, a process for connecting the chip 22 to the terminals 3 and 4 is performed.
A process of mounting the main body 2 on the chip 22 is performed. Thereby, as shown in FIG. 1E, a chip-type capacitor 1 in which the main body 2 is mounted on the chip 22 is completed.

Next, based on the block diagram shown in FIG. 3, a configuration centering on the image processing unit 25 as the image processing means in the appearance inspection apparatus 16 will be described.

The image processing section 25 has an A / D converter 26. The CCD camera 20 is connected to an A / D converter 26. The image data, which is an analog signal captured by the CCD camera 20, is A / A
It is converted into a digital signal by the D converter 26.
The A / D converter 26 includes an image memory 27 that stores digitized image data, a video mixer 28 that mixes and outputs input signals, and calculates the appearance of the image data from a predetermined calculation method. Calculation logics 29 are connected to each other. The image memory 27
The control logic 30 that defines each operation is connected to the calculation logic 29.

The image processing section 25 is provided with a CPU 31 as a control means for performing the calculation and control processing comprehensively. The CPU 31, the image memory 27, and the calculation logic 29 are connected bidirectionally.
The CPU 31 is connected to a ROM 32 as a storage unit that stores a control program and the like, and a RAM 33 as a storage unit that temporarily stores data such as input calculation values and test calculation results related to various display information. .

An input / output device 34 is connected to the CPU 31. A start means (not shown) for driving the visual inspection apparatus 16 is connected to the input / output device 34. Based on a predetermined start signal from the start means, C / C
An appearance inspection centering on the PU 31 is performed. Further, an inspection display unit (not shown) is connected to the input / output device 34, and outputs a determination signal as to whether or not the printing state of the capacitor 1 is normal from the CPU 31 to the separation processing device 17 or the like.

The input / output device 34 is further connected to a keyboard 35 as external input means or setting means.
Various settings relating to the appearance inspection are performed by the input operation of the keyboard 35. Further, a display monitor 36 as a display device is connected to the video mixer 28. The display monitor 36 includes a capacitor 1
An image is displayed based on a signal from the video mixer 28 so that the operator can recognize the appearance of the print surface 5, that is, the print state of the print surface 5 here.

Next, the appearance inspection apparatus 1 having the above configuration.
6 will be described with reference to a flowchart showing a processing procedure when the appearance inspection of one capacitor 1 shown in FIG. 4 is performed. This series of processing is executed by the control processing of the CPU 31.

First, in step S1, it is determined whether or not the capacitor 1 is present. As shown in FIG. 2, if the condenser 1 is arranged at a position facing the CCD camera 20, the reflected light from the condenser 1 illuminated by the illumination 19 is taken into the CCD camera 20. The determination is made, and the routine goes to the next step S2. On the other hand, when the condenser 1 is not at a position facing the CCD camera 20, the light from the illumination 19 is not captured by the CCD camera 20 as reflected light.
It is determined that the capacitor 1 does not exist, and the series of processing ends once.

In step S2, a process for setting a binarization threshold is executed. This processing is an arithmetic processing using the highest luminance value D1 and the lowest luminance value D2 among the image data which is the multi-value data taken in from the CCD camera 20. Specifically, the set value v is previously input from the keyboard 35, and the binarization threshold is calculated by substituting each value into the equation (D1-D2) · v + D2. Here, if 0.5 (50%) is set as the set value v, the binarization threshold is set to a central value between the highest value D1 and the lowest value D2 of luminance. As described above, since the binarization threshold is not fixed and is set each time, a suitable binarization threshold is set regardless of the change over time of the brightness of the illumination 19 or the difference in the print color density. Obtainable. Of course, by appropriately changing the setting value v to, for example, 0.45 or 0.6 by the input setting using the keyboard 35, it is also possible to obtain an optimal binarization threshold value according to the inspection environment and the like. Instead of taking the intermediate point as described above, it is also possible to set the binarization threshold value in consideration of the deviation of the luminance. In step S2, binarization processing of image data, which is multi-valued data, is performed based on the calculated binarization threshold. By this binarization processing, a binary image is obtained.

In FIGS. 6 and subsequent drawings, for convenience of explanation, the dark image of the binary image is indicated by hatching, and the printing surface 5, the polarity mark 6, the company mark 7, the lot number 8, Images corresponding to the display information of the capacitance value 9 and the voltage value 10 are also given the same reference numerals. In the following description,
Expressions such as up, down, left, and right are used based on the orientation of each piece of display information on the printing surface 6.

In step S3, a main body position measuring process is executed. This process measures the position of the surface of the main body 2, that is, the position of the printing surface 5, as shown in FIG. 6, based on the binary image obtained in step S2. In step S2, the upper end point P1, the right end point P2, and the lower end point P3 are measured based on the boundary between light and dark of the binary image. Also,
By performing arithmetic processing using these points P1 to P3, the center point P0 of the printing surface 5 is obtained. Further, a left end point P4 is obtained by performing arithmetic processing using these points P0 to P3. The reason why the left end point P4 is calculated is that the left end point P4 cannot be identified by the dark image corresponding to the polarity mark 6 and the dark image on the outer peripheral side of the main body 2.

At step S4, a window setting process is executed. Here, six windows are set,
These are all set on the basis of the coordinate values of the points P0 to P4 subjected to the measurement calculation processing in step S3. That is, as shown in FIG. 7, the window W1 is set to a vertically long rectangular shape including the upper end point P1, the window W2 is set to a horizontally long rectangular shape including the right end point P2, and the window W3 is set to the lower end point P
3 is set in a vertically long rectangular shape. The window W4 has a horizontally long rectangular shape on the printing surface 5, and the left side is a dark image corresponding to the polarity mark 6, and the right side is a bright image portion without other display information 7 to 10. Is set to The window W5 is set to a vertically long rectangular shape including all the dark images corresponding to the polarity marks 6 when printing is normal. The window W6 is set to have a rectangular shape including only the dark image corresponding to the polarity mark 6 and including all the dark images corresponding to the other display information 7 to 10. Each of these windows W1
To W6 are appropriately used in the following image inspection.

In step S5, a process for measuring the polarity mark 6 is performed. Here, as shown in FIG. 8, the left end point P4 is detected by the processing in step S3, and the window W4 and the window W5 are set by the processing in step S4. The width and area of the corresponding dark image are measured. The measurement of the width of the dark image corresponding to the polar mark 6 will be described. The left end of the dark image corresponding to the polar mark 6 is a left end point P4
However, the right end point is unknown. Therefore, when the window W4 is scanned from the right side, there is a point where the bright image is switched to the dark image, and this point can be regarded as the right end point. From these two points, the width t1 of the dark image corresponding to the polarity mark 6 is measured. Next, the area of the polar mark 6 is measured by the window W5. If the window W5 is normal, all the windows should be dark images.

At step S6, the quality judgment processing of the polarity mark 6 is executed. Here, it is determined whether or not each of the width t1 and the area of the dark image corresponding to the polarity mark 6 obtained in step S5 is within an allowable value. Each allowable value is set in advance via the keyboard 35. Specifically, if the width t1 is less than the preset allowable value or if the area is less than the preset allowable area value, the process jumps to step S19 to perform a defective item determination process.
For example, when the width t1 of the polar mark 6 is short, it is determined that the polar mark 6 of a necessary and sufficient size is not printed, and is determined to be defective. Also, the area of the polarity mark 6 (window W
5) is determined to be defective when there is a defect in printing or the like. On the other hand, if the measured width t1 and area are within the allowable values, the process proceeds to step S7 assuming that the polarity mark 6 is normally printed.

In step S7, a mask process is performed. The processing steps are executed to determine whether or not each of the display information 7 to 10 other than the polarity mark 6 is normally printed. Therefore, in step S7, first, the window W6 including these pieces of display information 7 to 10 is displayed.
Pay attention to. In window W6, each of these display information 7-1
Since the print surface 5 is circular, the upper right portion W6a of the window W6 is included in order to surely include all zeros.
And the lower right part W6b is approaching the dark image which is the background image. Accordingly, the upper right portion W6a and the lower right portion W6
b needs to be distinguished from the display information 7 to 10. Therefore, first, the average value of the brightness of the bright image portions of the windows W1 and W4 is calculated, and the background image around the printing surface 5 is processed so as to have the calculated brightness. As a result, the background image is regarded as a bright image, and the upper right portion W6a and the lower right portion W6b in the window W6 are also switched to the bright image. Note that the average value of the brightness of the window W1 and the window W4 is used because even if a bright image portion in one of the windows W1 or W4 includes an unscheduled print portion or the like, the average value is reliably obtained. This is to enable the mask processing to be executed.

In step S8, a character string extraction process is executed. In the following, characters and character strings are also used, which have the same meaning as display information including numbers, symbols, figures, and the like, and are used only for convenience of explanation. Here, as shown in FIG.
Is used, and the image in the window W6 is scanned from top to bottom. Then, there is a portion where a bright image is switched to a dark image. This is the upper end position of the dark image corresponding to the company mark 7. As the scanning is further continued, there is a portion where the dark image is switched to the bright image. This is the lower end position of the dark image corresponding to the company mark 7. When scanning is further continued, switching between a bright image and a dark image is repeated. Thereby, the heights h1, h2, h3, h4 of the respective dark images corresponding to the respective display information 7 to 10 and the heights H including all the dark images corresponding to the respective display information 7 to 10 are measured. .

In step S9, a determination process regarding the height of the entire character string is executed. Here, it is determined whether or not the overall height H of each of the pieces of display information 7 to 10 measured in step S8 is within a predetermined allowable value. This allowable value is set in advance via the keyboard 35. Specifically, when the height H does not fall within the preset allowable range (between the upper limit value and the lower limit value), the process jumps to step S19 to perform a defective product determination process. For example, each display information 7 to
In the case where 10 are overlapped with each other, the height H is shortened and it is determined to be defective. On the other hand, the measured height H
Is within the allowable value, the height H of the entire display information 7 to 10 is assumed to be normal, and the process proceeds to step S10.

In step S10, a determination process regarding the height of each character string is executed. Here, each height h1 to h for each of the display information 7 to 10 measured in step S8.
It is determined whether 4 is within a predetermined allowable value. This allowable value is set in advance via the keyboard 35. Specifically, when the heights h1 to h4 do not belong to a preset allowable range (between the upper limit value and the lower limit value), step S1 is executed.
The process jumps to step 9 to perform a defective item determination process. For example,
In a case where the upper half corresponding to the company mark 7 is not printed, the height h1 is shortened and is determined to be defective. On the other hand, if the measured heights h1 to h4 are all within the allowable value, the process proceeds to step S11 assuming that the heights h1 to h4 of the respective display information 7 to 10 are all normal.

In step S11, a width measuring process of each character string is executed. Here, the image of the window W6 subjected to the mask processing in step S7 is used.
The scanning from left to right and the scanning from right to left are performed on the images in. For example, in the portion corresponding to the dark image corresponding to the company mark 7, there is a portion where the image is switched from a bright image to a dark image when scanning from left to right. This is the left end position of the dark image corresponding to the company mark 7. Conversely, when scanning from right to left, there is a portion where a bright image is switched to a dark image. This is the right end position of the dark image corresponding to the company mark 7. Then, the same processing is executed for the other pieces of display information 8 to 10. Thereby, as shown in FIG. 10, each width d1, d2, d3, d4 of each dark image corresponding to each of the display information 7 to 10 is measured.

In step S12, a determination process regarding the width of each character string is performed. Here, each width h1 to h4 for each of the display information 7 to 10 measured in step S11.
Is within a predetermined allowable value. This allowable value is set in advance via the keyboard 35. Specifically, if the widths d1 to d4 do not fall within the preset allowable range (between the upper limit value and the lower limit value), the process jumps to step S19 to perform a defective product determination process. For example, in a case where the right half or the like corresponding to the lot number 8 is not printed, the width d2 becomes short and it is determined to be defective. On the other hand, if the measured widths d1 to d4 are within the allowable value, it is assumed that the widths d1 to d4 of the respective display information 7 to 10 are normal and the process proceeds to step S13.

In step S13, a process for extracting each character is executed. That is, in the above processing steps, the measurement processing and the determination processing are performed in units of character strings, but thereafter, the measurement processing and the determination processing are performed in more detail in each character unit, that is, the minimum unit. Here, description will be given focusing on display information of “50 V” which is a display of the voltage value 10 as shown in FIG. First, it is assumed that the number of character strings, the number of characters of each character string, the character type, and the like are set in advance by an input operation from the keyboard 36. In the present embodiment, the capacitor 1 is set before the appearance inspection. Are set for all the display information 6 to 10 in accordance with the type of. Thus, for example, if the voltage value is 10, the character string is the fourth column, and three characters are printed here. The three characters are character types of "5", "0", and "V" in order from the left. You can see that there is. Therefore, here, FIG.
As shown in FIG. 1A, a process is performed in which the width d4, which is a dark image having the voltage value 10 measured in step S8, is divided into three equal parts and each character is cut out. The dark image corresponding to “5” in the display information of the voltage value 10 is set to the image c1 and “0”.
The dark image corresponding to "V" will be described as an image c2, and the dark image corresponding to "V" will be described as an image c3. Then, each image c1 to c3
Are separated by bright image portions, which are gaps between characters. However, when the images c1 to c3 are close to each other or the intervals between them are irregular, the images c1 to c3 are added to the partition line.
May overlap, but in this case, a process of adjusting the position of the partition line to the left and right is performed. Thus, FIG.
As shown in (b), each of the images c1 to c3 is cut out individually. Then, for each of the images c1 to c3, FIG.
As shown in (c), a process for setting a circumscribed rectangle is executed. Also, the area occupied by the dark image in the circumscribed rectangle is measured.

In step S14, a determination process regarding the area of each of the images c1 to c3 is executed. Here, it is determined whether or not the area of each dark image for each of the images c1 to c3 measured in step S13 is within a predetermined allowable value.
This allowable value is set in advance via the keyboard 35.
Specifically, when each area does not belong to the preset allowable range (between the upper limit and the lower limit), step S19 is performed.
The process jumps to and performs the defective product determination processing. On the other hand, if each of the measured areas is within the tolerance, each of the images c1 to c1
Step S15 assumes that the area of each of the c3 is normal.
Move to.

In step S15, an expansion / contraction process is executed. Here, only the image c3 will be described, but it goes without saying that the processing is executed for all other images. In the RAM 33, as shown in FIG.
It merely stores dot data of 5 dots horizontally. Since only a very small amount of data needs to be stored in this way, the storage capacity of the RAM 33 is not wasted. The storage data i uses font data at the time of printing. An image c3 (see FIG. 11 (c)) actually obtained with respect to the stored data i has a large number of dots and cannot be directly compared. Therefore, a normalization process is performed prior to the expansion / contraction process. The normalization processing is processing for making the storage data i and the circumscribed rectangle of the actual image c3 the same. For example, as shown in FIG. 11C, the circumscribed rectangle of the image c3 is a vertical x
If the dot is a horizontal dot and a horizontal y dot, a process of adjusting the length and width of the storage data i is performed. More specifically, the storage data i is multiplied by x / 7 in the vertical direction and y in the horizontal direction.
/ 5 times. As a result, as shown in FIG. 12B, reference data I that is the same circumscribed rectangle as the image c3 is generated. Since the reference data I is generated by matching the vertical x and the horizontal y of the image 3c each time as described above, the size of the image c3 is different, or the image c3 is a vertically long or horizontally long image. Even in this case, the most optimal data can be provided as the reference data I.

After the normalization processing is completed, expansion / contraction processing of the reference data I is executed. First, the contraction processing will be described. Here, a thinning process is particularly executed among the contraction processes. Thinning is generally referred to as an operation of converting a linear figure into a sequence of points existing at the center of the width while maintaining the connectivity of the figure. , Thin line data Ia is generated as shown in FIG. In the general contraction processing, the obtained contraction data may be interrupted and the continuity may be lost. Therefore, when inspecting a continuous linear figure such as a character as in the present embodiment, the thinning processing is performed. It is preferred to apply. Next, the expansion process will be described. What is expansion?
This is an "operation for changing the neighborhood of one pixel to one", and is generally performed by adopting either a known "4-neighbor" or "8-neighbor" as the neighborhood. By performing the same processing, the expansion data Ib is generated as shown in FIG.

In step S16, a superposition process is performed. The data serving as a reference for the superimposition processing is the thin line data Ia and the expansion data Ib generated by the expansion / contraction processing in step S15. The comparison data superimposed on these is the image captured this time, which is the image c3 here. And FIG.
As shown in (a), a process of superimposing the thin line data Ia and the image c3 is performed. Further, as shown in FIG. 13B, a process of superimposing the expansion data Ib and the image c3 is performed.

In step S17, a judgment process of the degree of coincidence is performed on the result of the superposition in step S16. The allowable value of the degree of coincidence is set in advance by an input operation using the keyboard 35, for example, 98
% And the like can be set as required. Then, as a result of superimposing the thin line data Ia and the image c3, the thin line data Ia
a is 10 when all a are included in the dark image area of the image c3.
The coincidence is determined as 0%. In addition, the expansion data Ib
As a result of superimposing the image c3 and the image c3, the degree of coincidence is determined with the case where the image c3 is entirely included in the dark image area of the dilation data Ib as 100%. If one of the coincidences falls below the permissible value (lower limit), the process proceeds to step S19 to determine a defective product.

For example, as shown in FIG.
13 has a missing portion c3a, FIG.
As shown in (b), the protruding portion c3 of the image c3
When b is present, the degree of coincidence decreases, and when the degree of coincidence falls below the lower limit, which is the allowable value, it is determined to be defective. As a result, it is possible to reliably determine a defect, such as a loss or bleeding of a printed character in each character unit, which is the minimum unit, as a defect. On the other hand, if the coincidences are within the allowable values, it is determined that the print characters of the image c3 are normal, and the process proceeds to step S18.

In step S18, a non-defective item determination process is executed. That is, only the items that have cleared all of the above inspection items are determined to be non-defective, and steps S6 and S
Those which could not be cleared in 9, S10 and S17 are all judged to be defective in step S19, and the inspection process for one capacitor 1 ends. Note that the capacitor 1 determined to be defective in step S19
Is discarded after being separated from non-defective products by the separation processing apparatus 17 of FIG. On the other hand, the capacitor 1 determined to be non-defective in step S18 is conveyed to the chip mounting device 21 to be a chip-type capacitor 1 as a final product.

According to the appearance inspection apparatus 16 described above,
In the inspection of the printed surface 5 of the capacitor 1, an automatic inspection using image processing can be performed without visual inspection of an operator. As a result, the production efficiency of the capacitor 1 including the inspection is improved, and the manufacturing cost can be reduced.

Further, adverse effects due to visual inspection by an operator,
For example, it is possible to always judge whether the printing state is good or not at a constant level without variation in the judgment standard of the quality. As a result, variations among the products of the capacitor 1 are reduced.

Further, since the appearance inspection device 16 is incorporated in the printing device 11, it is possible to directly shift to the inspection after printing. Moreover, since the capacitor 1 is fixed by the chuck 18 from the time of printing to the time of inspection, the inspection can be performed while maintaining the posture of the capacitor 1 in the same state as at the time of printing.
There is no need to significantly correct the rotational position of the camera.
As a result, the inspection efficiency of the printing surface 5 is significantly improved.

The individual features relating to the inspection of the printing surface 5 will not be described in detail because they are clear from the description of each of the processing steps S1 to S19. The printed surface 5 can be simply inspected by various inspections such as an inspection in which the polarity mark 6 is distinguished from the other display information 7 to 10, a character string or character cutout processing, and a character matching degree inspection. In addition to this, there is an advantage that the quality can be properly determined.

In addition, steps S6, S9, S10, S
The setting values used in the determination processing in steps S12, S14, and S17 can be input and set via the keyboard 35, so that the print clarity, characters, and the like required for the display information 6 to 10 on the printing surface 5 can be set. It can be adjusted appropriately depending on the degree of the shape. Of course, for example, if there is a request that only the lot number 8 should be clarified, the criterion can be set strictly only for the set value in that part, so that the inspection according to the situation and the request can be easily realized. can do.

In this embodiment, the inspection object is the capacitor 1, especially the aluminum electrolytic capacitor.
The present invention is not limited to this, and other capacitors may be used. Further, the present invention is not limited to the capacitor, and may be another electric or electronic component. Further, the present invention is not limited to electric / electronic parts, and may be other articles.

In the present embodiment, the case where the printing state of the printing surface 5 is inspected has been described. However, the present invention is not limited to the case where the printing is performed, and other display information such as stamps and printed characters may be inspected. Good. That is, it is only necessary to assume that the luminance of the display information is different from that of the other parts.

The visual inspection device 16 is not attached to the printing device 11, but may be installed at a place where the display information can be separately inspected after the display information is attached to the inspection object, such as printing. Therefore, it may be installed independently of the printing device 11 or the like.

[Brief description of the drawings]

FIG. 1A is a schematic diagram of a printing apparatus and a chip mounting apparatus according to an embodiment, FIGS. 1B, 1C, and 1D are views showing an alignment state of capacitors, and FIG. FIG. 3 is a perspective view showing a capacitor.

FIG. 2 is a front view showing an inspection state by the visual inspection device.

FIG. 3 is a block diagram of a visual inspection device.

FIG. 4 is a flowchart showing an inspection procedure performed by the visual inspection device.

FIG. 5 is a plan view of a capacitor.

FIG. 6 is an explanatory diagram of an inspection image at the time of measuring a main body position.

FIG. 7 is an explanatory diagram of an inspection image when a window is set.

FIG. 8 is an explanatory diagram of an inspection image at the time of polar mark inspection.

FIG. 9 is an explanatory diagram of an inspection image at the time of mask processing.

FIG. 10 is an explanatory diagram of an inspection image when measuring the height and width of a character string.

11A is an explanatory diagram of an inspection image at the time of extracting each character, FIG. 11B is an explanatory diagram of an inspection image after each character is extracted,
(C) is an explanatory view of an inspection image when a circumscribed rectangle is set.

12A is an explanatory diagram of stored data, FIG. 12B is an explanatory diagram of reference data after normalizing the stored data,
(C) is an explanatory diagram of thin line data, and (d) is an explanatory diagram of dilation data.

13A is an explanatory diagram at the time of superposition processing with thin line data, and FIG. 13B is an explanatory diagram at the time of superposition processing with dilated data.

[Explanation of symbols]

1 ... Capacitor as inspection object, 2 ... Main body, 3,4
... Negative electrode terminal and positive electrode terminal as electrode terminals, 5... Printed surface as surface to be inspected, 6 to 10... Polarity mark as display information, company mark, lot number, capacitance value and voltage value, 11. Apparatus, 14 ... Print processing device as printing means, 16 ... Appearance inspection device, 18 ... Chuck as transfer means, 19 ... Lighting, 20 ... CCD camera, 25 ... Image processing unit as image processing means, 26 ... A / D converter, 27 image memory, 28 video mixer, 29 calculation logic, 30 control logic, 31 CP
U, 32: ROM as storage means, 33: RAM as storage means, 34: input / output device, 35: keyboard as input means, 36: display monitor as display means, W1 to W6: window, i: storage Data, I ...
Reference data, Ia: thin line data, Ib: dilation data.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2C061 AQ05 AS11 KK04 KK28 KK35 2F065 AA22 AA56 AA58 BB06 BB27 CC25 DD06 FF01 FF04 JJ03 JJ26 MM03 PP11 QQ03 QQ08 QQ23 QQ24 QQ25 QQ31 QQ32 QQ3 AQ03 SS03 EA11 EB01 ED01 ED05 ED15 ED21 5B057 AA01 BA02 BA29 CC02 CE03 CE04 CE09 CE12 DA03 DC33

Claims (16)

[Claims] 1. An appearance inspection apparatus for judging the quality of a plurality of types of display information attached to a surface of an inspection object, comprising: an imaging unit that receives light reflected from the surface; An image processing device that converts the obtained multi-valued image into a binary image, and determines whether display information is good or bad based on the binary image, wherein the image processing device divides the plurality of types of display information. A visual inspection apparatus for performing a pass / fail judgment process for each display information. 2. The visual inspection apparatus according to claim 1, wherein the image processing apparatus further performs a pass / fail determination process for each display information in a minimum unit such as a single character unit. 3. The multi-valued image according to claim 1, wherein the multi-valued image is converted into a binary image by the image processing apparatus, and a binarization threshold is set each time based on the luminance of the multi-valued image. The visual inspection device according to claim 1. 4. The image processing apparatus measures a surface position of the inspection object based on a binary image, sets a plurality of windows for the binary image based on the measurement result, and uses each window. The visual inspection apparatus according to claim 1, wherein the quality of each display information is determined. 5. The image processing apparatus sets a first window of the windows so as to straddle an area to which display information is attached and an area to which no display information is attached, and
5. The visual inspection device according to claim 4, wherein one end of the display information is determined by inspecting a binary image in the window. 6. The image processing apparatus according to claim 1, wherein the second window has a size and a position that include a plurality of predetermined pieces of display information and partially deviate from the surface of the inspection object. 6. The visual inspection apparatus according to claim 4, wherein, when each display information is inspected in the second window, a region on an outer peripheral side of the surface is masked. . 7. The image processing apparatus sets a third window of the windows so as to straddle the inside and outside of the surface of the inspection object, and uses at least the luminance of the third window to perform the mask processing. 7. The visual inspection device according to claim 6, wherein the inspection is performed. 8. The image processing apparatus according to claim 1, further comprising storage means for storing storage data of a minimum unit such as one character unit for each piece of display information, and storing the storage data stored in said storage means in a corresponding actual data. The reference data is generated by performing processing to match the vertical and horizontal size of the minimum unit data of the binary image, and the minimum unit data is compared with the minimum unit data of the actual binary image using the reference data. 8. The method according to claim 1, wherein the pass / fail is determined.
The visual inspection device according to any one of the above. 9. The image processing apparatus according to claim 1, further comprising storage means for storing storage data of a minimum unit such as one character unit for each piece of display information, and expanding and contracting using the minimum unit of the storage data. Processing is performed to generate dilation data and erosion data, and the minimum unit data of the actual binary image is compared with the dilation data and erosion data to check the degree of coincidence. 9. The visual inspection apparatus according to claim 1, wherein the quality of the unit is determined. 10. The visual inspection device according to claim 9, wherein the contraction processing is thinning processing, and the contraction data is thin line data. 11. The visual inspection according to claim 1, wherein a surface of the inspection object is a printing surface, and display information is printed on the printing surface. apparatus. 12. The visual inspection apparatus according to claim 1, wherein the surface of the inspection object has a circular shape. 13. The inspection object according to claim 11, wherein the object to be inspected is an aluminum electrolytic capacitor whose surface is formed of aluminum, and the printed surface has a different brightness from the ground color of the printed surface. Appearance inspection device. 14. The display apparatus according to claim 1, wherein the plurality of types of display information include at least a polarity mark and display information arranged in a plurality of levels, and the quality of the polarity mark is determined based on an inspection item different from other display information. The visual inspection device according to claim 13, wherein: 15. A printing apparatus comprising the appearance inspection apparatus according to claim 1. Description: 16. A printing apparatus, comprising: printing means for printing on the surface of an inspection object as display information; and transport means for transporting the inspection object from the printing means to a visual inspection apparatus, wherein the transportation means performs printing when the printing means performs printing. 16. The printing apparatus according to claim 15, wherein the inspection object is transferred while the posture of the inspection object is kept constant from the time when the inspection is performed by the appearance inspection device.